Atherosclerosis is a global concern and is a leading cause of cardiovascular events.1 Studies have shown that childhood cholesterol levels predict adult cholesterol levels, suggesting that children with high cholesterol levels are at high risk for atherosclerosis and early onset of coronary heart disease (CHD). Endothelial dysfunction, an important early event in the development of CHD,is present in children with high cholesterol levels before the formation of plagues within the arteries. The primary management of high cholesterol is lifestyle modification such as diet. Studies have shown that the Mediterranean diet is effective for the prevention of CHD. The cardioprotective effect of the Mediterranean diet may be attributed to the anti-oxidative and anti-inflammatory activities of the polyphenols abundant in the Mediterranean diet. Polyphenols are also known to improve vascular function by increasing the bioavailability of nitric oxide (NO), a potent endothelial-derived vasodilator. Several lines of evidence indicate that omega-3 fatty acid supplements also enhance endothelial function by stimulating release of NO from the endothelial cells, decreasing triglyceride concentration, and inhibiting platelet aggregation. Understanding the effect of dietary factors on biomarkers may provide insight into therapeutic strategies to reduce the burden of hyperlipidemia in children.